I was wondering if k20 and k30 frames for mid-80 chevy's are the same. I have a K30 mason dump with some frame rot and would like to do a swap. Thanks in advance.

No. A K20 frame is like a half ton. A K30 frame has much a much taller section through the area under and behind the cab.

I have investigated just this subject. I have asked around both here and on other forums, (there should be a thread started by me around pbb).. The answers i have gotten are that the frames are different. The K30 are beefier.

Thx GMCPete for finally spelling out the exact points. -I have a 86/K20 that i wanted to convert to a "real" K30.

Wrong sub-forum, but when were at it about the frames.. Does the Dodge W250/W350 frames differ? Or are they the 3/4 and 1-ton the same height/thickness?